99grandT:
different strokes for different folks!!
there are planes that beg for a 4-s, with time you will know!!, first steps are fine with 2-s, they are less $, are o.k. with 5-10% nitro & are simple in general, maybe your first biplane will bring the 4-s to you or a 3D plane!... but it will come.
Gostbear:
4-s donīt need as much oil as 2-s but benefits with more nitro in general; they need valve adjustment every so often but is no big deal, just read the manual, I use 12% oil, 15% nitro but I have read that saitoīs love nitro in high%.
enjoy!